Collapsible core.



Nm 875,097. PATENTED DEG. 31, 1907. G. F. MOKEE &- W.' F. SGHILLING.

GOLL'APSIBLB GORE. y APPLIOATION FILED 11119.16, i906.

tapered plug or center pin M y tomaran GEORGE F. MCKEE AND WILLIAM F. SCHILLING, OF ASPLIWALL, PENNSYLVNIA.

coLLAPsrBpn conn.

Specification of Letters,

Patented Esc. ,31, 19W?.

Appiicaion met August it. isos. saai no. 339.829.

T o all whom 'it may concern:

Be it known that we, GEORGE F. lzloKnn and WILLIAM F. SCHILLING, citizens ot the United States of America, residing at Aspinwall, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Collapsible Cores, of which the following is a specification, reierence being had therein to the accompanying drawing..

rlhis invention relates to collapsible cores for use in molding metal, and its primary object is toprovide a core so constructed as to compensate,` or allow for; the shrinkage of the metal forming the casting as it cools,

It is a well known fact in the molding art that the shrinkage ot' the molten'metal as it. cools within a mold is at the rate of oneeighth of an inch to the foot; and one ofthe serious obstacles to what is known as continuous molding or the repeated using ot a mold, without destroyin it, is the diiiiculty of allowing for this shrinlrage. i The. present invention a1msto overcome this diilculty by providing a collapsible core comprising Aa tapered center pin or lplug of wood, asbestos or other yielding material in combination with a core body made up of separable sectionshaving meeting surfaces beveled in such a'mannervv as to cause all ofA said sections to collapse or move towards the center of theA core, thus permittingA them to tree themselves readily from the casting without liability of cracking or otherwise damaging either the cast product or the mold.

The improved core is especially well adapted for casting pipes and conduits, pipe couplings and plumbers supplies generally, although the inventionis not' restricted to use for any 'particular line of castings.

The construction ofthe improvement will be `more fully described hereinafter in con- Liection with the accompanying drawing which forms a part of this specification, and its features of novelty will be defined in the appended claims. i

In the drawing, Figure 1 is a central longitudinal section vof a core embodying our invention, Fig. 2 is a transverse section of the same, Fier. 3 is an elevation-of one end of the improved core, on an enlarged scale, and Fig. lis an elevation ot' the opposite end of the same.

The reference numeral 1 designates a ade of' wood, estos, ber, or other yielding material.'

This tapered member of the core may be olf any desired shape in cross section but -is pret- 'erably round or square in cross section, the square form being here shown. Upon this central member are placed a series oi' core sections two or more of which are oppositely beveled to adapt them to serve. as key-pieces for the complete core. The key sections 2 and 3 are disposed on opposite sides ot the central plug or pin 1, and between these sections 2 and 3 are fitted other sections 4, 5, 6 and 7 the meeting edges 8 of which are so beveled as to direct all of said sections toward the center of the core, as illustrated by arrows in Fig. 4, when the tapered center plugis loosened or removed. The core sections -are composed of -any desirable tireproot material having a greater heat resisting quality than the'material to be cast, such materials as asbestos, copper, iron and comv position alloy, or the like, being advantageously employed. The material used for these core sections depends upon the nature of the material being cast, and it will. be understood that while we have specified certain materials which can be advantageously used, we do .not wish to confine ourselves to .the materials enumerated. lt will be noted Jfrom .this Fi 4 that if the core be removed or suflicienty'loosened to loosen the fric- :tional connection of the other core sections, the tendency oi all of said sections 'will be to collapse inward. The key pieces 2 and 3 will be directed toward each other and this. inward movement ot the key-pieces imparts a tendency to the other sections to move toward the center, thus insuring a practically equal collapsing movement throughout the circumference of the core. y 1

The im ortance of employing a central tapered p ug of soft material is that in the making` of certain castings, articularly heavy pipes, the contraction of t e soft central lug is frequentlysufficientto take up the shrinkage otthe-metal without loosening the plug and as such shrinkage is always toward the center the inward movement-oil the core sections toward the center distributes the strainy of the shrinkage4 equally toward the center avoiding undue binding and consequent cracking of the casting at any point.l It is obvious that the core may be easily removed from the casting by first removin the-central 'tapered plug and atterw'ard t e othercore sections.

As shown in Fig. ,2 more than a single sedesignated by same numerals in Figs. 3 and 4, but the core is enlarged bythe addition of a second series of sections numbered from 9 to 16. This particulailforinpi the core is adapted for the casting ,of a pipe connection 17 shown in Figs, `1 and @It Will thus be seen that the improved core isadapted'fcr a variety of castings, the requiredfcore sections necessaryto impart the desired 'contour to the article beingbuilt up around'thegtapered center pin. l'

1n employing our improved'core for light metal castings it is usually 4necessaryto loosen the tapered plug by a slightl blow on its smaller end at the proper time in the casting process, as the 'metal is not of suflicient strength or thickness 'to Vcompress the soft core plug tothe extent necessary to compensate'A for the shrinkage of the metal. f

The invention coinpiehends and includes all such constructions as fall Within the terms and vscope of the following claims, or Which embody the distinguishin features of the present improvement Whic 1 are the tapered pin ol' yielding material, in combination with core sections beveled to cause them to collapse toward the center of the core.

plurality of tapering core sections arranged' around the plug, each abutting the central pin or plug and arranged around the latter With their tapering ends extending in the opevene? posite direction to the tapering-end oi" the pin or plug, and having their meeting faces so disposed that all oi' the said core sections will move towards the center and collapse, when the centralpin 'or plug is removed.

2'. A collapsible core compri-sing a central pin or plug of yielding material, tapering 'rom one end to the other, and a plurality of core sections arranged around the plug, and each abutting the plug7 the said core sections having their meeting faces so disposed as to match neatly with each other and. with the central pin or plug and With the latter to form a practically solid core When the sections are in assembled position, the said meeting faces of the core sectionsk being also disposed so that ,all oli' the sections will move to- Ward the center and collapse when the tapering plug ,or pin is removed.

3. A collapsible core comprising a tapered central pin or plug of, yielding material, and a body portion .consisting of separable core sections arranged around the center core of plug with their meeting faces so disposed as to en- 'gage throughout with the plug and adjacent core sections to torni a practically solid core, the said meeting faces of the core sections being so disposed that all of said core section .will tend 'to move towards the center and collapse When the tapering pin or plug is Withdrawn.

In testimony whereof I'atlix my signature in the presence of two Witnesses.

GEORGE F. MGKEE. WILLIAM F. SCHLLING.

Witnesses:

BEssiE Lou/REY, W. P. Loi/vani?. 

